Which of the following is true of the time measurement systems used by ancient mesoamerican and south american cultures?

the incas, aztecs, and mayans all had calendars.
the incas and aztecs had calendars, but the mayans did not.
the incas and mayans had calendars, but the aztecs did not.
the incas had calendars, but the mayans and aztecs did not.

The correct answer is that all of them had calendars. Besides of calculating the passage of time, the calendars in Mesoamerican cultures were very important for religious, astronomical and cultural purposes among those civilizations, such as divination and social events.

in 1989, tiananmen square in beijing was the site of china’s main industries. china’s government headquarters. -pro-democracy demonstrations. (second choice)

thurgood marshall

explanation: in 1954, thurgood marshall and a team of naacp attorneys won brown v. board of education of topeka, kansas. in this landmark decision, the supreme court held that segregation in public education violated the equal protection clause of the fourteenth amendment.